All About Vitamin B12 - Ask a Nutritionist

November 5, 2026

Could low vitamin B12 be contributing to your fatigue, brain fog, or tingling in your hands and feet? Registered dietitian Britni Vincent explains why vitamin B12 is essential for energy metabolism, red blood cell production, and nervous system health. Learn the common signs and causes of B12 deficiency, which foods provide this important nutrient, and who may be at greater risk of low levels. Plus, discover when B12 testing and supplements may be helpful, how different supplement forms compare, and why taking extra B12 doesn't necessarily boost energy if your levels are already adequate.